Priority is claimed on Japanese Patent Application No. 2003-282671, filed Jul. 30, 2003, and Japanese Patent Application No. 2003-288081, filed Aug. 6, 2003, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a power tailgate apparatus that opens and closes a tailgate of a vehicle using electric power.
2. Description of Related Art
As a power tailgate apparatus that opens and closes a tailgate of a vehicle using electric power, a technology is known that opens and closes the tailgate that is connected to a curved arm by moving a rack gear in a longitudinal direction of a vehicle via a pinion gear using electric power, and turns a slide roller of the curved arm that is linked to the rear end side of the rack gear in an arc shape, while guiding it using a curved guide that has the same curvature as the curved arm (see, for example, U.S. Pat. No. 6,142,551 (this document is referred to below as “Patent Document 1”)). In this power tailgate apparatus, the rack gear that turns the curved arm is able to move in the vehicle longitudinal direction while swinging in a vertical direction.
In the power tailgate apparatus disclosed in the Patent Document 1, because the rack gear that turns the curved arm is able to move in the vehicle longitudinal direction while swinging in a vertical direction, there is a problem that a cover that covers the rack gear on the vehicle interior side drops downwards, and it becomes difficult to secure sufficient head clearance above the head of a passenger. In addition, because the curved arm is connected to the rear end portion of the rack gear, it is necessary to provide an electric motor and a decelerator including the pinion gear in the vicinity of the tailgate aperture, and the space utilization of the area around the tailgate aperture is poor.
Accordingly, a first object of the present invention is to provide a power tailgate apparatus that can secure head clearance above the head of a passenger and can improve space utilization in the area around a tailgate aperture.
In addition, in the power tailgate apparatus disclosed in the Patent Document 1, because the slide roller of the curved arm that is linked to the rear end side of the rack gear is turned in an arc shape while being guided by a curved guide that has the same curvature as the curved arm, there is a problem that, in particular, in the initial opening action of the tailgate, considerable slide resistance is reduced, and thus that energy transfer performance for opening the tailgate is poor.
Accordingly, a second object of the present invention is to provide a power tailgate apparatus that can secure head clearance above the head of a passenger and can improve space utilization in the area around a tailgate aperture, and that can also reduce slide resistance in the initial stage of opening action of the tailgate.